Hitachi, Ltd.

Hitachi Device Engineering Co., Ltd.

Hitachi Displays, Ltd.

Other

Akira Shingai

Kikuo Ono

Junichi Hirakata

Naoki Tokuda

Junichi Hitachi Ltd Int Prop Gp Hirakata

Kikuo Hitachi Ltd Int Prop Gp Ono

The present invention provides a driving method for a display device which includes a display part having pixels of M columns&#xd7;N rows and a memory, wherein each pixel includes a light emitting element and a driving transistor for driving the light emitting element. At times other than a usual light emitting time, a driving voltage is applied to the driving transistor of each pixel so as to turn on the light emitting element of each pixel, a value of current which flows in the light emitting element of each pixel is detected, correction data for each pixel is calculated based on the detected value of current, and the calculated correction data for each pixel is stored in the memory. At the usual light emitting time, a driving voltage which is based on data which is obtained by adding the correction data stored in the memory to video signal data is applied to the driving transistor of each pixel.

Driving method of display device

In a liquid crystal display device having a backlight, the backlight has a first state which outputs a first amount of light and a second state which generates a second amount of light and the time for the first state and the time for the second state are controlled. Due to such a constitution, the liquid crystal display device can display clear motion picture images in spite of a simple constitution thereof. Further, the liquid crystal display device can display clear and bright motion picture images.

Liquid crystal display device

A liquid crystal display device includes a liquid crystal display panel having plural pixels, a lighting device having at least one light source and projecting light generated by the light source on the liquid crystal display panel, and a circuit supplying a first current during a first period and a second current smaller than the first current during a second period to the light source alternately. The circuit includes a current monitoring circuit which measures the first current and the second current, and a light control circuit which adjusts a ratio of the first period to the second period based upon a signal from the current monitoring circuit.

Liquid crystal display device having an improved lighting device

A liquid crystal display device includes a liquid crystal display panel and a lighting device. The lighting device is supplied with alternately a first current during a period t and a second current during a second period t such that electric power E is lower than electric power E . E is defined as (t &times;i (1)&times;V (1))/2&plus;(t &times;i (2)&times;V (2))/2, where i (1)&equals;a peak-to-peak value of the first current, V (1)&equals;a peak-to-peak value of a voltage across the light source during the period t1, i (2)&equals;a peak-to-peak value of the second current, and V (2)&equals;a peak-to-peak value of a voltage across the light source during the period t . E is defined as (t &plus;t )&times;I &times;V , where I and V are effective values of the current and voltage of the light source, respectively.

Growing community of inventors

Chiba, Japan

Akira Shingai